Note: Descriptions are shown in the official language in which they were submitted.
TEST D~VICE HANDLING ~YSTEM
~ie1d of ~e ~nvention
The present invention rela-tes to apparatus and pro~
cess for handling flexible objects, especially test devices
used in the determination of a particular constituent
in a sample. More particularly, it is concerned with
vacuum apparatus and a process capable of removing one
test device at a time from a cartridge or magazine con-
taining multiple test devices.
sackground of the Invention
Increasingly, test devices in the form of reagent
-strips are being used to provide convenient and rapid
analysis of various types of samples, including samples
o-f biological, industrial and automotive fluids, wines,
1~ and the like. Diagnostic test devices designed for
detecting various clinically significant substances or
constituellts in biological fluids, such as urine and
blood, including lysed or unlysed blood, blood plasma
and blood serwll, have in many cases supplanted prior
wet chemistry techni(lues which were both cumb~rsome
and time consuming. These diagnostic test deYices
have thus assisted in the fast and accurate cliagnosis
and treatment of disease.
Conventional test devices generally comprise an
absorbent or porous matrix incorporated with indicator
reactant~, usually of a colorimetric nature. The
sample to be tested is contacted with the matrix, such
as by momentary immersion where the sample is liquid,
and the indicator response is observed after a period
of time. For example, in the detection of occult
5 blood in urine a diagnostic test device can be employed
which comprises an absorbent paper impregnated with
o-tolidine and peroxide. When this test device is
wetted with urine containing occult blood, decomposi-
tion of the peroxide occurs with the accompanying
10 oxidation of the o-tolidine to provide a color response.
This test is sensitive and extremely useful in diag-
nosing urinary tract disorders.
For ease in handling, the absorbent or porous
matrix, sometimes called a "carrier matrix", is advan-
15 tageously affixed to an insoluble support member suchas an organo-plastic strip, e.g., polystyrene, by
suitable means such as double faced adhesive tape.
Optically transparent substrate-material known as
TRYC~* polystyrene film made by Dow Chemical Company,
20 is preferred. The support member normally has a
thic~ness of about .19Omm, a width of about 5mm and a
length which can vary depending on the intended use, the
number of reagent areas present, et cetera. Currently,
test devices are being made by the .~mes Division of Miles
25 Laboratories, Inc. which have lengths of about 85.5mm
and about 8~.5mm. Obviously, based on these dimensions
and the materials involved, such test devices tend to be
small, elongated and flexible in nature. While these test
devices are easily manageable during manual handling
30 operations, automated handling is another matter.
With the need for automated equipment employing test
devices for determining constituents in fluids, especially
for performing multiple diagnostic tests, it is essential
that a mechanical system be devised which is capable of
35 rapidly, accurately and reliably handling one test
device at a time. The removal of a single test device
* Tr~rk
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from a cartrid~e or magazine containing multiple test
devices to permit the transfer of the single test device
to another portion of a system for contact with a
sample to be tested is, therefore, a key to automating
5 such testing.
In one very special case, i.e., very small test
devices which contain a single rea~ent area, apparatus
has been developed for ejecting one test device at a
time from a magazine or cartridge containing multiple
1~ test devices of a similar nature. Generally, the
substrate for such test devices is only slightly larger
than the dimensions of the absorbent matrix, which
normally measures about 5mm by about lOmm. Typically,
the magazine or cartridge is spring loaded and the configura-
15 tion is such that only one test device at a time canbe ejected when pressure is applied to one edge of the
bottommost test device.
- For standard test devices having elongated dimensions
as set forth above, however, there is no apparatus
20 available for removing one test device at a time from
a cartridge or magazine containing other test devices.
The system employed in the special case of very small
test devices is not effective for use with standard
test devices. Accordingly, for both medical and indus-
25 trial applications which require automation there is aneed for fool-proof test device handling apparatus cap-
able of removing a single test device from a cartridge
or magazine in order that that single reagent test
device can be transferred to another portion of the
30 automated system.
S~mmar~ of t~e Invention
An o~ject of the present invention is to provide
means for removing a single test device at a time from
a cartridge or magazine containing multiple test devices.
~nother object of the present invention is to pro-
vide ~or automated test device handling which is capable
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of rapidly, accurately and reliably removing a single test device frcm a
cartridge or magazine oontaining multiple test devioe s.
In acoordan oe with the present invention, test device handling apparatus
and a process are disclosed which involves a cartridge or magazine capable
of retaining multiple test devices resting on each other, the test devices being
retained inside the magazine by detents located on both sides of an opening
in the bottom of the cartridge or magazine, and vacuum means for causing the
bottommost test device in the car-tridge or magazine to flex sufficiently
to pass over the detents and be removable from the cartridge or magazine
while other test devices remain in the cartridge or magazine. Each detent
comprises a ledge extending at an angle greater than 90 and less than 180
from an end wall of said magazine.
Description of the Drawings
Other and further objects, advantages and features of the invention will
be apparent to those skilled in the art frcm the following detailed des-
cription th~reof, taken in conjunction with the accompanying drawings, in
which:
Fig. 1 shows a general vi~ow of the system (but with different detents)
portions thereof being shown in cross section,
Fig. 2 is a top view of the apparatus in Fig. 1, taken along lines 2-2;
Fig. 3 is an enlarged cross sectional drawing of the portion of Fig. 1
illustrated by dotted line, and
Fig. 4 is an embodi~ent of a car-tridge or magazine for holding test devices
which can ke utilized in the present invention, said cartridge or n~gazines
being shown in cross section and showing the particular detent arrangement
of this invention.
-4a~
Description of Preferred Eh~xx~ments
In Figs. 1 and 2 a cartridge or magazine 10 for test devices, such as
reagent strips, is shown. Magazine 10, as illustrated, is open at the top
and has rigid side walls 11 and 12 which together with rigid end walls 13
S2~
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and 14 form an elongated rectangular shaped container
having interior dimensions slightly larger than tes-t
devices 16 contained therein. The bottom o magazine
10 has an opening 18 the width of which is equal -to
5 the width of the interior dimensions o~ magazine 10
formed by the interior of side walls 11 and 12 and the
length o~ which is sli~htly smaller than -the interior
dimensions of side walls 13 and 1~. End member 20 ancl
21 whicll extend a-t ri~ilt angles to side walls 13 and
10 1~ of magazine 10 fornl detellts or led~es at either
end of openillg 1~ for retainin8 test devices 16 inside
magazine 10. Thus the bottommost test devices 16
inside magazine 10 is retained in magazine lQ solely by
the detents or ledges formed by end members 20 and 21
15 and other test devices 16 are supported by the bottom-
most test device recting one upon the other in parallel
layered fashion.
The positioning of the test devices 16 inside maga-
zine 10 is best illustrated in Fig. 3 ~hich shows a
20 lower corner of magazine 10 in enlarged cross section.
This Figure illustrates how the test devices 16 rest one
upon the ot~er in parallel fashion inside magazine 10
with the bottommost test device 16 being held inside
container 10 by the detents or ledges formed by the end
25 members. T]le bottommost test device 16 is thus not
supported at any other point e~cept at its extreme ends
by end members 20 and 21. Other test devices 16 inside
magazine 10 rest one upon the other as illustrated in
Figs. 1 and 3 and are so positioned inside magazine
3n 10 that reagent matri~ areas 23 and 2~ which are
attached to a suitable substrate 26 face upward :in a
direction opposite opcning lS.
Beneath lllagazine 10 and aligned ~ith opening 18 is
vacuum transport means or pickup head 2~ having a housing
35 30 with an open chamber 32 at its top which is connected
~ ~ ~ 5 2 ~
by means of conduit 34 to a vacuum source ~not shown).
Vacuum transport means 28 is capable of moving in at
least two directions, up and down, and the dimensions
of this member are sucll t11at upper sur~ace 35 of vacuum
5 transport menas 2S can enter opening lg of magazine 10
and contact the lower surface of substrate 26 of the
bottommost test device 16 insidc magazine 10.
In operation, magazine 10 normally is retained in
a vertical position and loaded ~ith multiple test
10 devices 16 positioned insicle maga7ine 10 in tlle manner
illustrated by Figs, 1, 2 alld 3. Test devices 16 are
then rernoved one at a time from magazine 10, as required,
~y moving vacuum transport means 2S upward through opening
18 such that the top surface 35 of vacuum transport means
15 28 rests against substrate 26 of the bottommost test
devices 16 inside maga7ine 10. By then applying a vacuum
~hrough conduit 34 the bottommost test device 16 can be
held by the pressure exerted against chamber 32 of vacuum
transport means 28 and said test device will move down-
20 ward as vacuum transport means 28 moves downward. Bypulling downwardly at the center of the bottommost test
device 16 vacuum transport means 28 causes the flexible
substrate 26 of said test device to flex and slightly
distort into a U-shaped configuration in which the center
25Of the bottommost test device 16 is lower than the ends
of said test device held by the detents formed by end
members 20 and 21. As vacuum transport means 28 con-
tinues to move downwardly the distortion of the bottom-
most test device 16 continues until the ends of said
30test device becorne released from the detents formed by
end members 20 and 21 and test device 16 is thereby
removed from magazine 10. Due to the fact that only the
bottommost test devicc is distorted or flcxed at any
given time the other test devices remain inside magazine
3510 as the bottomlllost test dcvice 16 is witlldrawn tllrough
opening 18. Once removed from Inagazine 10 a test device
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16 can be transferred by vacuum transport means 28 or any other suitable
means to a different location. Following such transfer the same or a
different vacuum transport means 28 can be used to remove another test
device 16 from magazine 10.
I-t should be understood that the materials used Eor construction of magazine
10 and vacuum transport means 28 are not critical and may be of any suitable
rig.ici or semi-rigid material, such as metal, plastic, etc. Although the side
walls oE magazine 10 are normally continuous, retainers in the form of rod
members may be used in place of continuous wcills. As indicated abo~e, the
interior dimensions of magazine 10 must be such that multiple test devices 16
can be inserted into the magazine with sufficient tolerance to prevent binding
between the test devices and the side walls. The detents or ledges retaining
the bottcmmost test device 16 in magazine 10 need be only the minimum width
necessary to provide su~port such that the weight of the test devices inside
magazine 10 will not c~use the bottcxrmost or lowest test device 16 to pass
through opening 18 until that test devi oe is r2moved by vacuum transport means
28. Obviously, chamker 32 of vacuum transport means 28 may take many different
configurations, such as a rectangular configuration, an eliptical configuration,
a circular configuration, etc. In fact, chamker 32 need not be a single
cham~er, but may consist of multiple chambers. The top surface 35 of vacuum
transport means 28 is preferably flat, but may be slightly curved so as to
better adap-t-to -the flexed configuration of the bottcmmost -test device 16 as that
test devi oe is removed from magazine 10 -through opening 18.
Figure 4 shc~s the preferred shape oE ledges or de-tents formecl by end
members 20 and 21. In figure 4 tapered end members 39 and 40 ace illustrated~
-these each provide a ledge extending at an angle greater than 90 and less
-than 180 Ercm an end wall of the magazine. The detents of the magazine
10 n~l,' c~ L~ Sl~ ted (il`` a manner not shc~), such that pressure
ap?lied to the ~ ents ~ '.},'? ~ten.- t~ n~)ve ~slightly thereby
facilitatiny ~le release of a single flexible n2~ er at a time fr~r~ ga~ e
10 .
W~ile norrnally magazine 10 will ~e po~sl~ioned in a vertical or upright
~osltion, sl~ch tha-t the fle~ible nem~ers ~vn'.ail~d Lherein rest one u~on the
other by means of gravity, the concept of the present invention is applicable
to pressure feed sys-tems which by n~ans of spring loading or other suitable
pressure are capable of h~lding multiple flexible members in place against
the detents or end n~nbers of the cartridge or maaazine 10. Thus, if desired,
test devices 16 could be held by suitable means, such as a spring n~nber (not
shown), against end m~mbers ~0 and 21. For such loading maga~ine 10 would not
need to be positioned in an upright position.
Frcm the foregoing, it will be seen that this invention is well adapted
to attain all of the ends and objects herein above set forth, together with
other advantages w~ich are obvious and which are inherent to the system.
The present invention p ~ nits a single flexible object, such as a test device,
to be removed from a container holding multiple rlexible objects. While
the invention has been described with particularity to test devices
such as reagent s-trips, it will be understood tha-t the
sys-tem and handling apparatus may be used for the handling
of other elongated fle~ible members such as thin metallic
or plastic members. Thc pick-up ilead and maga~ine of the
present invention permi-t systems to be automated by
assuring the retrieval and delivery of one flexible mem-
ber at a t:ime.
Obviously, many other modifications and variations
of the invention as hereinbe~ore set forth may be made
without departing from the spirit and scope thereof.
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